For user verification and other purposes, many devices such as portable computers and cellular telephones include a fingerprint sensor. A fingerprint sensor, sometimes called a biometric sensor, senses a fingerprint of a finger place on the fingerprint sensor. The obtained fingerprint is compared to an authorized user's stored fingerprint. If there is a match, the user is verified.
The finger placed on the fingerprint sensor may have an electrostatic charge. As the finger nears or contacts the fingerprint sensor, this electrostatic charge is discharged as an electrostatic discharge (ESD).
To prevent the ESD from damaging the fingerprint sensor, a grounded metal bezel is mounted near the fingerprint sensor. The grounded metal bezel discharges the ESD from the finger contacting the fingerprint sensor. However, the metal bezel is expensive, costly to attach, and results in assembly yield loss due to mold flash on the metal bezel.
In the following description, the same or similar elements are labeled with the same or similar reference numbers.